1. Field
One or more embodiments relate to a fixing device that reduces abrasion between a fixing belt and a nip forming member, and an image forming apparatus including the fixing device.
2. Description of the Related Art
Electro-photographic image forming apparatuses supply a toner to a latent image formed in a photoconductor to form a visible toner image, transfer the toner image to a recording medium, and fixes the transferred toner image to the recording medium to print an image on the recording medium.
To fix the toner image transferred to the recording medium in a process of printing the image on the recording medium, the image forming apparatus may include a fixing device that heats and presses the recording medium to which the toner image is transferred.
The fixing device may include a pressure roller that presses the recording medium and a fixing belt that rotates when the fixing belt contacts an outer surface of the pressure roller and that heats the recording medium. A pressure roller and a nip forming member that forms a fixing nip on a contact portion of the fixing belt are disposed in an inner surface of the fixing belt.
Such a fixing device has a structure in which the fixing belt rotates with respect to the nip forming member, and thus, friction occurs in a portion where the fixing belt comes into contact with the nip forming member. A difference in speed may occur between the fixing belt and the pressure roller due to the friction, and torque of equal to or greater magnitude than a predetermined magnitude may be applied to the pressure roller. Thus, a slip phenomenon which an unfixed toner image slips on the recording medium may occur. Abrasion may occur in the nip forming member or the fixing belt due to the friction. In a case where such abrasion becomes severe, the fixing belt may be damaged. In order to prevent the slip phenomenon and damage to the fixing belt, a lubricant may be coated on a region between the fixing belt and the nip forming member to reduce friction therebetween.
The lubricant may stay between the fixing belt and the nip forming member for a long time in order to be stably fixed. However, the lubricant coated on the region between the nip forming member and the fixing belt may move in association with the rotation of the fixing belt to thereby leak to the outside, which may lead to slip and damage even when a large amount of lubricant is coated on the region between the nip forming member and the fixing belt at a time.